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6,569 results for “Long-term”
Apparent breeding success drives long-term population dynamics of a migratory swan
<p>The ability of a species to adapt to environmental change is ultimately reflected in its vital rates – i.e., survival and reproductive success of individuals. Together, vital rates determine trends in numbers, commonly monitored using counts of species abundance. Rapid changes in abundance can give rise to concern, leading to calls for research into the biological mechanisms underlying variations in demography. For the NW European population of Bewick's swan (<i>Cygnus columbianus bewickii</i>), there have been major changes in the population trends recorded during nearly five decades of monitoring (1970-2016). The total number of birds increased to a maximum of c. 30,000 in 1995 and subsequently decreased to about 18,000 individuals in 2010. Such large fluctuation in population numbers is rare in long-lived species and understanding the drivers of this population change is crucial for species management and conservation. Using the integrated population model (IPM) framework, we analysed three demographic datasets in combination: population counts, capture-mark-resightings (CMR) and the proportion of juveniles in winter over a period of ~50 years. We found higher apparent breeding success in the years when the population had a positive growth rate compared to years with a negative growth rate. Moreover, no consistent trend in adult and yearling survival, and an increasing trend in juvenile survival was found. A transient life-table response experiment showed that apparent breeding success and adult survival contributed most to the variation in population trend. We explored possible explanatory variables for the different demographic rates and found a significant association between juvenile survival both with the water level in lakes during autumn migration, which affects food accessibility for the swans, and with summer temperatures. Such associations are important for understanding the dynamics of species with fluctuating population sizes, and thus for informing management and conservation decisions.</p>
Long-term effects of antibiotic treatments on honeybee colony fitness – a modelling approach
<p><b>1.</b> Gut microbiome disequilibrium is increasingly <span>implicated </span>in host fitness reductions, including for the economically important and disease-challenged western honey bee, <i>Apis mellifera</i>. In lab experiments the antibiotic tetracycline, which is used to prevent American Foulbrood Disease in countries including the US, elevates honey bee mortality by disturbing the microbiome. It is unclear however, how elevated individual mortality affects colony level fitness.</p> <p><b>2.</b> We used an agent-based model (BEEHAVE) and empirical data to assess colony level effects of antibiotic-induced worker bee mortality, by measuring colony size. We investigated the relationship between the duration that the antibiotic-induced mortality probability is imposed for and colony size.</p> <p><b>3.</b> We found that when simulating antibiotic-induced mortality of worker bees from just 60 days per year, up to a permanent effect, the colony is reduced such that tetracycline treatment would not meet the European Food Safety Authority's (EFSA) honey bee protection goals. When antibiotic mortality was imposed for the hypothetical minimal exposure time, which assumes that antibiotics only impact the bee's fitness during the recommended treatment period of fifteen days in both spring and autumn, the colony fitness reduction was only marginally under the EFSA's threshold.</p> <p><b>4.</b> Synthesis and Applications: Modelling colony level impacts of antibiotic treatment shows that individual antibiotic-induced honey bee worker mortality can lead to colony mortality. To assess the full impact, the persistence of antibiotic-induced mortality in honey bees must be determined experimentally, <i>in vivo</i>. We caution that as the domestication of new insect species increases, maintaining healthy gut microbiomes is of paramount importance to insect health and commercial productivity. The recommendation from this work is to limit prophylactic use of antibiotics and to not exceed recommended treatment strategies for domesticated insects. This is especially important for highly social insects as excess antibiotic use will likely decrease colony growth and an increase in colony mortality.</p>
Data of socio-technical evaluation of long-term spent nuclear fuel management options at San Onofre, California
<p>Data file supporting the socio-technical evaluation of long-term spent nuclear fuel management options at San Onofre, California.</p>
Numerical response of predators to large variations of grassland vole abundance and long-term community change
<p>Voles can reach high densities with multi-annual population fluctuations of large amplitude, and they are at the base of predator communities in Northern Eurasia and Northern America. This status places them at the heart of management conflicts wherein crop protection and health concerns are often raised against conservation issues.<strong> Here, a 20-year survey describes the effects of large variations in grassland vole populations on the densities and the daily theoretical food intakes (TFI) of vole predators based on roadside counts.</strong> Our results show how the predator community responded to prey variations of large amplitude and how it reorganized with the increase in a dominant predator, here the red fox, which likely negatively impacted hare, European wildcat and domestic cat populations. This population increase did not lead to an increase in the average number of predators present in the study area, suggesting compensations among resident species due to intra-guild predation or competition. Large variations in vole predator number could be clearly attributed to the temporary increase in the populations of mobile birds of prey in response to grassland vole outbreaks. Our study provides empirical support for more timely and better focused actions in wildlife management and vole population control, and it supports an evidence-based and constructive dialogue about management targets and options between all stakeholders of such socio-ecosystems.</p> <p>The data set includes:</p> <p><b>S1 kml file</b>. Location of the study area (can be dropped in a Google Earth window or read from a GIS)</p> <p><b>S2 Excel file.</b> Road-side counts (sheet 1) and list of species observed (sheet 2)</p> <p><b>S3 Excel file.</b> Small mammal data</p> <p><b>S4 Excel file.</b> Data for computing theoretical daily food intakes</p> <p> </p>
Can we predict global patterns of long-term climate change from short-term simulations?
<p>Post-processed data from "Can we predict global patterns of long-term climate change from short-term simulations?". Also includes python dictionary for translating file code into the name of the run. For use with code publicly available on github.com/lm2612/Ridge_3 and github.com/lm2612/GPRegression.</p>
Long-term monitoring reveals forest tree community change driven by atmospheric sulfate pollution and contemporary climate change
Aim: Montane environments are sentinels of global change, providing unique opportunities to assess impacts on species diversity. Multiple anthropogenic stressors such as climate change and atmospheric pollution may act concurrently or synergistically in restructuring communities. Thus, a major challenge for conservation is untangling the relative importance of different stressors. Here, we combine long-term monitoring with multivariate community modeling to estimate the anthropogenic drivers shaping forest tree diversity along an elevational gradient. Location: Camels Hump Mountain, Vermont, USA Methods: We used Generalized Dissimilarity Modelling (GDM) to model spatial and temporal turnover in beta diversity along an elevational gradient over a 50-year period, and tested for spatiotemporal shifts in density and elevational distribution of individual species. GDMs were used to predict community turnover as non-linear functions of changes in elevation, climate and atmospheric pollution. Results: We observed significant shifts in elevational range and density of individual species, which contributed to an overall reduction in the elevational gradient in beta diversity through time. GDMs showed the combined effects of sulfate deposition and temperature as drivers of this temporal reduction in beta diversity. Spatiotemporal changes differed among species, with shifts observed both up and downslope. For example, in a reversal of a previous upslope range contraction, red spruce (Picea rubens Sarg.) increased in density and shifted downslope since the 1990's, occupying warmer, drier climates. Main conclusion: Our results demonstrate that global change is impacting the stratification of forest tree diversity along elevational gradients, but the responses of individual species are complex and variable in direction. We suggest abiotic drivers may directly impact individual species while also indirectly altering species interactions along elevational gradients. Our approach modelling the drivers of compositional turnover quantifies the rate and amount of change in beta diversity along environmental gradients, and serves as a powerful complement to studying species-specific responses.
Long-Term Stable Metal Organic Framework (MOF) Based Mixed Matrix Membranes for Ultrafiltration
<p><strong>Preprint available here:</strong> Al-shaeli, Muayad; Smith, Stefan J. D.; Jiang, Shanxue; Wang, Huanting; Zhang, Kaisong; Ladewig, Bradley P. (2020): Long-Term Stable Metal Organic Framework (MOF) Based Mixed Matrix Membranes for Ultrafiltration. ChemRxiv. Preprint. <a href="https://doi.org/10.26434/chemrxiv.13399367.v1">https://doi.org/10.26434/chemrxiv.13399367.v1</a></p> <p>Published manuscript: Muayad Al-Shaeli, Stefan J.D. Smith, Shanxue Jiang, Huanting Wang, Kaisong Zhang, Bradley P. Ladewig,<br> Long-term stable metal organic framework (MOF) based mixed matrix membranes for ultrafiltration,<br> Journal of Membrane Science, 2021, 119339, <a href="https://doi.org/10.1016/j.memsci.2021.119339">https://doi.org/10.1016/j.memsci.2021.119339</a></p> <p><strong>Abstract</strong></p> <p>In this study, novel mixed matrix membranes (MMMs) were synthesized by adding metal organic frameworks (MOFs) (UiO-66 and UiO-66-NH<sub>2</sub>) to pristine and sulfonated polyethersulfone (PES). The differing synthetic method resulting in MMM where additives were grafted to the matrix polymer, or formed a natural interface, allowing the impact of these MMM features to be investigated. The composite membranes were characterised by FTIR, PXRD, water contact angle, porosity, pore size, etc. Membrane performance was investigated by water permeation flux, flux recovery ratio, fouling resistance and anti-fouling performance. The stability test was also conducted for all the prepared mixed matrix membranes. A higher reduction in the water contact angle was observed after adding both MOFs to the PES and sulfonated PES membranes compared to pristine PES membranes. An enhancement in membrane performance was observed by embedding the MOFs into PES membrane matrix, with flux increased remarkably (565 LMH for PES+UiO-66-NH<sub>2</sub> at 5% loading and 487.1 LMH for SPES-UiO-66(10% binding) while the BSA rejection was still kept at a high level. By adding the MOFs into PES matrix, the flux recovery ratio was increased greatly (more than 99% for most mixed matrix membranes). The mixed matrix membranes showed higher resistance to protein adsorption compared to pristine PES membranes. After immersing the membranes in water for 3 months, 6 months and 12 months, both MOFs were stable and retained their structure. This study indicates that UiO-66 and UiO-66-NH<sub>2</sub> are great candidates for designing long-term stable mixed matrix membranes (MMMs) for applications in water and wastewater treatment.</p>
DNA methylation following long-term pulmonary multi-walled carbon nanotubes exposure in mice
<p>Whole Genome Bisulphite Sequencing (WGBS) experiment to assess DNA methylation patterns in mice lungs 56 days after exposure to Multi-Walled Carbon NanoTubes (MWCNTs). The doses of MWCNTs used in this experiment were 0, 40 or 80 μg/mouse. In this record, we provide WGBS coverage files along with bedgraph files.</p>
Data from: Long-term monitoring of seed dispersal by Asian elephants in a Sundaland rainforest
<p><span><span><span><span><span><span><span><span><span><span><span>Asian elephants (<i>Elephas maximus</i>) have inhabited almost all forests in tropical Asia until recently, yet little is known about their role in ecological processes, particularly in the Sundaic forests of Southeast Asia. These forests are peculiar in their phenology, with supra-annual and highly irregular episodes of mast fruiting. Here we present a long-term (six-year) monitoring of the seeds dispersed by elephants in dipterocarp forests of northern Peninsular Malaysia. We conducted monthly dung surveys at two mineral licks (11.3 km apart) frequently visited by elephants. Additionally, we recorded haphazard observations of seeds and seedlings in elephant dung at other locations. We recorded a minimum of 48 morphospecies from at least 25 plant families dispersed by elephants. Elephant seed dispersal was very heterogenous in space, with only 30.3 % of the morphospecies dispersed at both sites (Jaccard dissimilarity index = 0.48). Temporally, elephants dispersed seeds in sporadic pulses of abundance and diversity, without any apparent seasonality (seeds appeared in 19.1 % of 1,284 dung piles and 57.1 % of the 63 months in which we found dung) and with long periods without any seed being dispersed. Nearly half (48 %) of the plants dispersed by elephants belong to a megafaunal dispersal syndrome. Our long-term approach allowed us to unravel an important aspect of Asian elephants' role and effectiveness in the seed dispersal cycle. Sundaland's forests are undergoing a rapid loss of their previously common megaherbivores (rhinos and elephants), with profound and long-term consequences for ecosystem functioning.</span></span></span></span></span></span></span></span></span></span></span></p>
The long-term effect of restoration interventions, landscape composition, and time on the restoration success of Pannonic sand grasslands
<p>Data for the manuscript</p>
Long-term movements and home range changes: rapid territory shifts in meerkats
<p>1. Territoriality and stable home ranges are a common space use pattern among animals. These ranges provide its inhabitants with important resources and thus favourable territories are associated with an increased fitness. While the role of territory quality and changes of territory ownership have often been investigated, the changes of territorial boundaries have been less studied.</p> <p>2. Here we investigated space use changes in a social mammal species, applying a novel analytical approach, calculating long-term dissimilarity in space use using distance matrices based on periodic utilization distributions. This approach makes it possible to identify different space use patterns, which cannot be distinguished by only considering changes between consecutive time periods.</p> <p>3. We analysed meerkat (Suricata suricatta) movements of a total of 24 different groups over a 16-year period, resulting in 134 group years. We then correlated the identified home range changes to life history events and possible environmental drivers.</p> <p>4. Groups had stable territories for several years before they abandoned their home range mostly to move quickly to new areas where they again remained for several years. Of 26 identified sudden shifts, 22 occurred in the summer months and often involved distances larger than the original home range size. Home-range movements that were close together in time were often also spatially clustered and moved in a similar direction. These shifts were often preceded by more frequent interactions between groups, but did not seem to be a product of direct displacements by other groups. The normalized difference vegetation index (NDVI) as a measure of food production and social factors such as dominance changes did not correlate to changes.</p> <p>5. Against our expectation space use changes were not accumulations of small changes, but more often involved long distance moves into unknown ranges. This means that the groups enter areas where they cannot profit from local knowledge. The methods used identifies episodes of long stability alternated by sudden changes in meerkats and in general provides insight into long-term space use. Our methods can be used to analyse long-term space use, either within or across species.</p>
Data from: Distance-dependent seedling mortality and long-term spacing dynamics in a neotropical forest community
Negative distance dependence (NDisD), or reduced recruitment near adult conspecifics, is thought to explain the astounding diversity of tropical forests. While many studies show greater mortality at near vs. far distances from adults, these studies do not seek to track changes in the peak seedling curve over time, thus limiting our ability to link NDisD to coexistence. Using census data collected over 12 years from central Panama in conjunction with spatial mark-connection functions, we show evidence for NDisD for many species, and find that the peak seedling curve shifts away from conspecific adults over time. We find wide variation in the strength of NDisD, which was correlated with seed size and canopy position, but other life-history traits showed no relationship with variation in NDisD mortality. Our results document shifts in peak seedling densities over time, thus providing evidence for the hypothesized spacing mechanism necessary for diversity maintenance in tropical forests.
Data from: Ecological network inference from long-term presence-absence data
Ecological communities are characterized by complex networks of trophic and nontrophic interactions, which shape the dy-namics of the community. Machine learning and correlational methods are increasingly popular for inferring networks from co-occurrence and time series data, particularly in microbial systems. In this study, we test the suitability of these methods for inferring ecological interactions by constructing networks using Dynamic Bayesian Networks, Lasso regression, and Pear-son's correlation coefficient, then comparing the model networks to empirical trophic and nontrophic webs in two ecological systems. We find that although each model significantly replicates the structure of at least one empirical network, no model significantly predicts network structure in both systems, and no model is clearly superior to the others. We also find that networks inferred for the Tatoosh intertidal match the nontrophic network much more closely than the trophic one, possibly due to the challenges of identifying trophic interactions from presence-absence data. Our findings suggest that although these methods hold some promise for ecological network inference, presence-absence data does not provide enough signal for models to consistently identify interactions, and networks inferred from these data should be interpreted with caution.
Long-term research and hierarchical models reveal consistent fitness costs of being the last egg in a clutch
1. Maintenance of phenotypic heterogeneity in the face of strong selection is an important component of evolutionary ecology, as are the consequences of such heterogeneity. Organisms may experience diminishing returns of increased reproductive allocation as clutch or litter size increases, affecting current and residual reproductive success. Given existing uncertainty regarding trade-offs between the quantity and quality of offspring, we sought to examine the potential for diminishing returns on increased reproductive allocation in a long-lived species of goose, with a particular emphasis on the effect of position in the laying sequence on offspring quality. 2. To better understand the effects of maternal allocation on offspring survival and growth, we estimated the effects of egg size, timing of breeding, inter- and intra-annual variation, and position in the laying sequence on gosling survival and growth rates of black brent (Branta bernicla nigricans) breeding in western Alaska from 1987–2007. 3. We found that gosling growth rates and survival decreased with position in the laying sequence, regardless of clutch size. Mean egg volume of the clutch a gosling originated from had a positive effect on gosling survival (β = 0.095, 95% CRI: 0.024, 0.165), and gosling growth rates (β = 0.626, 95% CRI: 0.469, 0.738). Gosling survival (β = -0.146, 95% CRI: -0.214, -0.079) and growth rates (β = -1.286, 95% CRI: -1.435, -1.132) were negatively related to hatching date. 4. These findings indicate substantial heterogeneity in offspring quality associated with their position in the laying sequence. They also potentially suggest a trade-off mechanism for females whose total reproductive investment is governed by pre-breeding state. 20-Mar-2020
Chemical variations in Quercus pollen as a tool for taxonomic identification: implications for long-term ecological and biogeographical research
<p><strong>Aim</strong> </p> <p>Fossil pollen is an important tool for understanding biogeographic patterns in the past, but the taxonomic resolution of the fossil-pollen record may be limited to genus or even family level. Chemical analysis of pollen grains has the potential to increase the taxonomic resolution of pollen, but present-day chemical variability is poorly understood. This study aims to investigate whether a phylogenetic signal is present in the chemical variations of <em>Quercus</em> L. pollen and to assess the prospects of chemical techniques for identification in biogeographic research.</p> <p><strong>Location</strong> </p> <p>Portugal</p> <p><strong>Taxon</strong> </p> <p>Six taxa (five species, one subspecies) of <em>Quercus</em> L., <em>Q. faginea, Q. robur, Q. robur</em> ssp. <em>estremadurensis, Q. coccifera, Q. rotundifolia</em> and <em>Q. suber</em> belonging to three sections: <em>Cerris, Ilex</em>, and <em>Quercus</em> (<a href="https://www.biorxiv.org/content/10.1101/761148v2#ref-13">Denk, Grimm, Manos, Deng, & Hipp, 2017</a>)</p> <p><strong>Methods</strong> </p> <p>We collected pollen samples from 297 individual <em>Quercus</em> trees across a 4° (∼450 km) latitudinal gradient and determined chemical differences using Fourier-transform infrared spectroscopy (FTIR). We used canonical powered partial least-squares regression (CPPLS) and discriminant analysis to describe within- and between-species chemical variability.</p> <p><strong>Results</strong> </p> <p>We find clear differences in the FTIR spectra from <em>Quercus</em> pollen at the section level (<em>Cerris</em>: ∼98%; <em>Ilex</em>: ∼100%; <em>Quercus</em>: ∼97%). Successful discrimination is based on spectral signals related to lipids and sporopollenins. However, discrimination of species within individual <em>Quercus</em> sections is more difficult: overall, species recall is ∼76% and species misidentifications within sections lie between 18% and 31% of the test-set.</p> <p><strong>Main Conclusions</strong> </p> <p>Our results demonstrate that subgenus level differentiation of <em>Quercus</em> pollen is possible using FTIR methods, with successful classification at the section level. This indicates that operator-independent FTIR approaches can surpass traditional morphological techniques using the light microscope. Our results have implications both for providing new insights into past colonisation pathways of <em>Quercus</em>, and likewise for forecasting future responses to climate change. However, before FTIR techniques can be applied more broadly across palaeoecology and biogeography, our results also highlight a number of research challenges that still need to be addressed, including developing sporopollenin-specific taxonomic discriminators and determining a more complete understanding of the effects of environmental variation on pollen-chemical signatures in <em>Quercus</em>.</p>
Data from: Long-term population dynamics of dreissenid mussels (Dreissena polymorpha and D. rostriformis): a cross-system analysis
Dreissenid mussels (including the zebra mussel Dreissena polymorpha and the quagga mussel D. rostriformis) are among the world's most notorious invasive species, with large and widespread ecological and economic effects. However, their long‐term population dynamics are poorly known, even though these dynamics are critical to determining impacts and effective management. We gathered and analyzed 67 long‐term (>10 yr) data sets on dreissenid populations from lakes and rivers across Europe and North America. We addressed five questions: (1) How do Dreissena populations change through time? (2) Specifically, do Dreissena populations decline substantially after an initial outbreak phase? (3) Do different measures of population performance (biomass or density of settled animals, veliger density, recruitment of young) follow the same patterns through time? (4) How do the numbers or biomass of zebra mussels or of both species combined change after the quagga mussel arrives? (5) How does body size change over time? We also considered whether current data on long‐term dynamics of Dreissena populations are adequate for science and management. Individual Dreissena populations showed a wide range of temporal dynamics, but we could detect only two general patterns that applied across many populations: (1) Populations of both species increased rapidly in the first 1–2 yr after appearance, and (2) quagga mussels appeared later than zebra mussels and usually quickly caused large declines in zebra mussel populations. We found little evidence that combined Dreissena populations declined over the long term. Different measures of population performance were not congruent; the temporal dynamics of one life stage or population attribute cannot generally be accurately inferred from the dynamics of another. We found no consistent patterns in the long‐term dynamics of body size. The long‐term dynamics of Dreissena populations probably are driven by the ecological characteristics (e.g., predation, nutrient inputs, water temperature) and their temporal changes at individual sites rather than following a generalized time course that applies across many sites. Existing long‐term data sets on dreissenid populations, although clearly valuable, are inadequate to meet research and management needs. Data sets could be improved by standardizing sampling designs and methods, routinely collecting more variables, and increasing support.
Lateralisation of short- and long-term visual memories in an insect
The formation of memories within the vertebrate brain is lateralised between hemispheres across multiple modalities, however, in invertebrates evidence for lateralisation is restricted to olfactory memories, primarily from social bees. Here we use a classical conditioning paradigm with a visual conditioned stimulus to show that visual memories are lateralised in the wood ant, Formica rufa. We show that a brief contact between a sugar reward and either the right or left antenna (reinforcement) is sufficient to produce a lateralised memory, even though the visual cue is visible to both eyes throughout training and testing. Reinforcement given to the right antenna induced short-term memories whereas reinforcement given to the left antenna induced long-term memories. Thus, short- and long-term visual memories are lateralised in wood ants. This extends the modalities across which visual memories are lateralised in insects and suggests that such memory lateralisation may have evolved multiple times, possibly linked to the evolution of eusociality in the Hymenoptera.
Data from: Plant demographic and functional responses to management intensification: a long-term study in a Mediterranean rangeland
1. Understanding how functional traits, which are key for plant functioning, relate to demographic parameters of populations is central to tackle pending issues in plant ecology such as the forecast of the fate of populations and communities in a changing world, the quantification of community assembly processes or the improvement of species distribution models. We addressed this question in the case of species from a Mediterranean rangeland of southern France. 2. Changes in species abundance in response to management intensification (fertilization and increased grazing pressure) were followed over a 28-year period. Probabilities of presence, and elasticities of the changes in the probability of space occupancy to colonization and survival, which are analogues of demographic parameters, were calculated for 53 species from the time series of abundance data using a space occupancy model. Nine quantitative traits pertaining to resource use, plant morphology, regeneration and phenology were measured on these species and related to demographic parameters. 3. The long-term dynamics of species in response to management intensification was associated with major changes in functional traits and strategies. Changes in the probability of occurrence – analogous to population growth rate - were correlated with traits describing the fast-slow continuum of leaf functioning. The elasticity of population growth rate to colonization was significantly related to reproductive plant height and seed mass, and to a lower extent, to leaf carbon isotopic ratio. 4. Synthesis. The functional response of species to management intensification corresponds to a shift along the second axis of a recently identified global spectrum of plant form and function, which maps, to some extent, onto the fast-slow continuum of life-history strategies. By contrast, the elasticity of colonization relates to the global spectrum axis capturing the size of organs. Seed mass contributes to this axis and is assumed to relate to one of the important traits structuring the reproductive strategy axis of life histories as well, namely net reproductive rate. While this mapping between functional and life-history traits is appealing, further tests in contrasting types of communities are required to assess its degree of generality.
A Test of the Repeatability of Measurements of Relative Fitness in the Long-Term Evolution Experiment with Escherichia coli
<p>Experimental studies of evolution using microbes have a long tradition, and these studies have increased greatly in number and scope in recent decades. Most such experiments have been short in duration, typically running for weeks or months. A venerable exception, the long-term evolution experiment (LTEE) with <i>Escherichia coli</i> has continued for 30 years and 70,000 bacterial generations. The LTEE has become one of the cornerstones of the field of experimental evolution, in general, and the BEACON Center for the Study of Evolution in Action, in particular. Science laboratories and experiments usually have finite lifespans, but we hope that the LTEE can continue far into the future. There are practical issues associated with maintaining such a long-term experiment. One issue, which we address here, is whether key measurements made at one time and place are reproducible, within reasonable limits, at other times and places. This issue comes to the forefront when one considers moving an experiment like the LTEE from one lab to another. To that end, the Barrick lab at the University of Texas at Austin, measured the fitness values of samples from the 12 LTEE populations at 2,000, 10,000, and 50,000 generations and compared the new data to data previously obtained at Michigan State University. On balance, the datasets agree very well. More generally, this finding shows the value of simplicity in experimental design, such as using a chemically defined growth medium and appropriately storing samples from microbiological experiments. Even so, one must be vigilant in checking assumptions and procedures given the potential for uncontrolled factors (e.g., water quality) to affect outcomes. This vigilance is perhaps especially important for a trait like fitness, which integrates all aspects of organismal performance and may therefore be sensitive to any number of subtle environmental influences.</p>
Data from: Long-term climate and competition explain forest mortality patterns under extreme drought
Rising temperatures are amplifying drought-induced stress and mortality in forests globally. It remains uncertain, however, whether tree mortality across drought-stricken landscapes will be concentrated in particular climatic and competitive environments. We investigated the effects of long-term average climate [i.e. 35-year mean annual climatic water deficit (CWD)] and competition (i.e. tree basal area) on tree mortality patterns, using extensive aerial mortality surveys conducted throughout the forests of California during a 4-year statewide extreme drought lasting from 2012 to 2015. During this period, tree mortality increased by an order of magnitude, typically from tens to hundreds of dead trees per km2, rising dramatically during the fourth year of drought. Mortality rates increased independently with average CWD and with basal area, and they increased disproportionately in areas that were both dry and dense. These results can assist forest managers and policy-makers in identifying the most drought-vulnerable forests across broad geographic areas.
ScienceDex guides
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These curated guides explain access requirements, typical timelines, costs, and reuse considerations for widely used research datasets.
Allen Brain Atlas
Allen Brain Atlas is an Allen Institute collection of brain map atlases, datasets, APIs, and analysis tools covering mouse, human, and non-human primate brain resources.
Annotated Behaviour and Observability Dataset (ABODe)
ABODe is a University of Edinburgh DataShare dataset for behavior classification in group-housed mice using home-cage video, identities, bounding boxes, ground-plate positions, and annotator labels.
DANDI Archive for NWB datasets
DANDI is a BRAIN Initiative archive for publishing and sharing neurophysiology data, including electrophysiology, optophysiology, and behavioral data packaged as NWB and related standards.
International Brain Laboratory public data
The International Brain Laboratory public data releases expose standardized mouse decision-making experiments, including Neuropixels recordings, widefield calcium imaging, behavior, and session metadata accessed through the ONE API.
OpenNeuro
OpenNeuro is a free, open platform for sharing neuroimaging datasets, with public search, dataset pages, and download paths for web, S3, DataLad, and the OpenNeuro CLI.